Interchangeable die transfer station, joining tool system and joining method

ABSTRACT

A transfer station for temporarily storing at least one interchangeable die. The die can be removed by a joining tool to carry out a joining operation, and can be returned back into the transfer station after the joining operation. The transfer station including a die receptacle for holding the die, and a rotating device for rotating the die in the receptacle in order to establish an axial engagement between the die and the joining tool.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of international applicationPCT/EP2014/076387, filed Dec. 3, 2014 which claims priority from GermanPatent Application No. DE102013021055.0 filed Dec. 18, 2013, thedisclosures of which are incorporated herein by reference in theirentirety.

The present invention relates to transfer station for temporarilystoring at least one interchangeable die, wherein the interchangeabledie can be taken out of the transfer station by a joining tool to carryout at least one joining operation which uses the interchangeable dieand can be stored back in the transfer station again once the joiningoperation has been carried out, said transfer station having at leastone interchangeable die receptacle for receiving the interchangeabledie.

In addition, the present invention relates to a joining tool systemhaving a joining tool which comprises a die receiving portion, having amultitude of interchangeable dies which comprise a die head and a dieshank, and having such a transfer station.

Finally, the present invention relates to a method for joining by meansof a joining tool which comprises a die receiving portion for aninterchangeable die, said method having the steps—move the joining toolto a transfer station in which an interchangeable die is temporarilystored, transfer the interchangeable die into a die receiving portion ofthe joining tool, wherein a relative axial movement is effected betweenthe die receiving portion and the interchangeable die and finally carryout a joining process using the interchangeable die.

BACKGROUND OF THE INVENTION

The interchangeable dies in question can be used for clinching or forriveting, in particular for punch riveting. The die feature can be, forexample, an axial recess which is realized in the manner of a truncatedcone, with or without an elevation in the centre, etc.

The joining tool can be a tool which is suitable for the abovementionedjoining process and comprises in particular a C-frame, on the one leg ofwhich the tool, such as for example a punching tool, is arranged, and onthe other leg of which the interchangeable die is secured.

A hitherto usual concept for fastening the interchangeable die on thedie receptacle consists in providing a transverse bore toward the shankreceptacle in the die receiving portion. The interchangeable die can besecured by means of said transverse bore, for example using a grubscrew. This type of fastening, however, allows for an automated changeof die only at great expense. In addition, the transverse bore iscomparatively large such that as regards strength the die receivingportion is weakened.

To avoid the last-mentioned problem, it is known from document DE 202006 013 082 U1 to provide a die receiving portion with a bore,fastening means which are supported on the bore wall of the diereceiving portion being provided in the bore in order to fasten a toolor a tool holder releasably on the die receiving portion. This can beeffected, for example, as a result of a threaded engagement or as aresult of a screw which cooperates with a tool holder by means of thebore, but from an end which is opposite the die. For axial securement,the document also describes providing clamping means which can berealized according to the end face wedge principle or are realized usingelastomer elements.

Although the problem of having to provide a transverse bore in the diereceiving portion for securing the die is avoided in this way, anautomatic die change can still only be realized with difficulty.

Interchangeable dies which can be exchanged comparatively simply areknown, for example, from document DE 103 35 085 A1. The interchangeabledies shown here comprise a die head and a die shank, a radial groovebeing realized on the die shank. Quick change receiving means, which canbe realized, for example, as latching, tightening or clampingconnections, can be provided on a C-frame. In addition, the documentdiscloses a changing station in which tool-heads and dies can be held instorage.

BRIEF SUMMARY OF THE EMBODIMENTS

Against said background, it is an object of the invention to provide animproved transfer station, an improved joining tool system and animproved joining method, wherein an automated die change at a joiningtool is possible. The automated change, in this case, is preferably tobe realizable on the one hand as quickly as possible. On the other hand,high holding forces, which prevent the interchangeable die beinginadvertently pulled out of the die receiving portion after a joiningoperation, are preferably to be set up nevertheless in the axialdirection between the interchangeable die and the die receiving portion.

Said object is achieved in the case of the transfer station named in theintroduction in that a rotating device for rotating the interchangeabledie is provided such that when the interchangeable die is taken out ofstorage, a rotate/insert connection between the interchangeable die andthe joining tool can be set up.

In the case of the joining tool system named in the introduction, theabove object is achieved in that the interchangeable dies areconnectable to the die receiving portion of the joining tool in eachcase by means of a rotate/insert connection, wherein the transferstation is preferably realized for the purpose of holding theinterchangeable dies at their die head.

In the case of the interchangeable die mentioned in the introduction,the fastening contour is preferably realized such that an insert/rotateconnection can be set up between the interchangeable die and the joiningtool.

In the case of the joining tool, a fastening device is preferablyrealized such that an insert/rotate connection can be set up between theinterchangeable die and the joining tool.

Finally, the above object is achieved in the case of the joining methodnamed in the introduction in that when the interchangeable die is takenover in the transfer station, the interchangeable die rotates.

The rotation of the interchangeable die is preferably effected aroundthe longitudinal axis of the interchangeable die.

In the transfer station, an interchangeable die received therein ispreferably held in a positive locking manner in the axial direction ofthe interchangeable die.

An insert/rotate connection is to be understood as a connection which isset up as a result of a relative axial offset between theinterchangeable die and the joining tool and a relative rotationaloffset between the interchangeable die and the joining tool, it beingpossible to effect said two relative offsets one after another ortogether at least partially superimposed.

In addition, an insert/rotate connection is to be understood as such aconnection where the relative rotation to set up the insert/rotateconnection extends over an angle of rotation of <360°, in particular<180°. It is particularly preferred when the angle of rotation to set upthe insert/rotate connection is within a range of between 30° and 150°,in particular within a range of between 45° and 135°. In a preferredembodiment, the angle of rotation is precisely 90°.

The insert/rotate connection, in this case, can be effected as a resultof directly rotating the interchangeable die relative to the diereceiving portion. However, it is also possible that the rotationalmovement is set up by a further component, for example a closure ring,as is used in some bayonet connections.

Consequently, the insert/rotate connection can be realized as a resultof two simple movements, namely a longitudinal movement to insert thedie shank into the shank receiving means and a rotational movement at adefined angle of rotation. Such types of movements can be automated in acomparatively simple manner and can be carried out quickly such thatautomated die changes are easy to realize.

In addition, an insert/rotate connection of this type can be realizedsuch that high holding forces can be set up in the axial directionagainst the die being pulled out of the die receiving portion.Consequently, the joining tools can also be used “overhead” and the diebeing removed inadvertently after a joining operation can also beprevented in a reliable manner.

By the transfer station preferably being realized for the purpose ofholding the interchangeable dies at their die head, it is possible for adie shank of the interchangeable dies to be freely accessible in eachcase. As a result, the interchangeable die can be taken over in thetransfer station by a joining tool by a die receiving portion beingmoved in the axial direction toward the interchangeable die in such amanner that the die shank is inserted into a shank receiving means ofthe die receiving portion.

As a result of the measure of carrying out a rotation of theinterchangeable die in the case of the joining method according to theinvention when the interchangeable die is taken over in the transferstation, it is additionally possible to set up a rotate/insertconnection between the interchangeable die and the joining tool when theinterchangeable die is transferred into a die receiving portion.

The fastening contour is preferably realized such that at least oneaxial portion of the fastening contour extends proceeding directly froma shank end face of the die shank. The fastening contour is preferablynot rotationally symmetrical. In addition, the fastening contour can berealized in a uniform or continuous manner, but can also consist ofseveral individual contour portions which are not connected to oneanother.

An interchangeable die is preferably to be understood as a one-piececomponent where the die head and the die shank are connected togetherintegrally. In general, however, it is also possible to provide theinterchangeable die by means of a standard die in connection with a dieadapter. In this case, the fastening contour can be realized on a shankof the adapter, and the die can be realized with a simple die shankwithout a fastening contour which is inserted substantially permanentlyinto a receiving portion of the die adapter, for example by means of agrub screw as in the prior art.

The object is consequently fully achieved.

In the case of the transfer station according to the invention, it isadvantageous when the rotating device is realized for the purpose ofrotating an interchangeable die which is received in the interchangeabledie receiving means.

In general, it is also certainly conceivable to provide such a rotatingdevice in such a manner that an interchangeable die is firstly removedfrom the interchangeable die receiving means and is then rotated. As aresult of the measure of rotating the interchangeable die in theinterchangeable die receiving means itself, the transfer station is ableto be realized in a structurally simple manner.

In one embodiment, it is preferred when the transfer station comprises adie rotary drive for rotating the rotating device.

In this connection, the rotational movement of the interchangeable dieis realized as a result of the die rotary drive. The operation ofrotating the interchangeable die, in this case, is able to be set upwith greater reliability.

The die rotary drive can be a pneumatic drive, for example a pneumaticcylinder being coupled with a translation-rotation converter. The dierotary drive, however, can also be another arbitrary drive, for examplean electromotive drive.

According to an alternative embodiment, the rotating device is realizedfor the purpose of being rotated by the joining tool.

In the case of this embodiment, the rotating device is a passive devicewhich enables rotatability of the interchangeable die in the transferstation. The driving force for rotating the interchangeable die isapplied, in the case of said embodiment, however, directly or indirectlyby means of the joining tool.

A direct transmission of force from the joining tool onto the rotatingdevice is to be understood, for example, as the joining tool being usedas an actuator.

The joining tool is preferably guided by a robot. Said robot can beprogrammed such that the joining tool cooperates, for example, directlywith the rotating device in order to rotate the same.

An indirect transmission of force is to be understood as the force beingeffected by means of an interchangeable die. For example, when movinginto the transfer station, the die can actuate a slide which rotates therotating device by means of a gear unit. It is also conceivable that inthe case of an interchangeable die with a helix-shaped fasteningcontour, a relative axial movement between the interchangeable die andthe joining tool causes a rotational movement of the interchangeable diewhich then serves to rotate the rotating device.

All in all, it is additionally advantageous when the interchangeable diereceiving means comprises a U-shaped portion into which theinterchangeable die can be inserted in a direction transversely withrespect to its longitudinal axis.

This type of embodiment of the interchangeable die receiving meansenables, on the one hand, a positive locking connection between theU-shaped portion and the interchangeable die in the axial direction ofthe interchangeable die as soon as the interchangeable die is insertedinto the U-shaped portion. On the other hand, in the case of said typeof insertion of the interchangeable die into the interchangeable diereceiving means (and removal from the same) the joining tool can beguided in a comparatively simple manner such that, for example, robotprogramming is simplified.

In general, it is conceivable for the interchangeable die to be rotatedby means of a separate device in the transfer station.

It is particularly preferred, however, when the U-shaped portion isitself realized so as to be rotatable relative to a base of the transferstation.

As a result, the interchangeable die can be rotated once theinterchangeable die has been inserted into the U-shaped portion.

In this connection, it is preferred that the U-shaped portion in thecase of said embodiment preferably cooperates with a rotary entrainmentcontour of the interchangeable die in order to secure theinterchangeable die in a positive locking manner in the direction ofrotation in the received state and to entrain it in the direction ofrotation in the case of a rotational movement of the U-shaped portion.

In addition, it is advantageous when the U-shaped portion is movable inrelation to a base of the transfer station between a transfer positionand a locked position in such a manner that in the transfer position theinterchangeable die is insertable into the interchangeable die receivingmeans and in the locked position is held securely in the transferstation.

As mentioned above, the interchangeable die is held in a positivelocking manner in the U-shaped portion preferably both in the axialdirection and in the circumferential direction. As a result of realizinga locked position, which is preferably achieved as a result of arotational movement of the U-shaped portion, the interchangeable die canalso be received in a positive locking manner in the radial direction inthe transfer station such that inadvertent removal or inadvertentexchange of interchangeable dies can be excluded.

All in all, it is additionally advantageous when the interchangeable diereceiving means is provided on a base of the transfer station, whereinthe base is mounted in a floating manner in relation to a stationaryframework of the transfer station.

This makes it possible for the base to carry out compensating movementswhen taking interchangeable dies out of storage and putting them backinto storage. As a result, operating reliability can be increased andwear and tear can be reduced.

The floating bearing arrangement can be effected, for example, by one orseveral elastomer elements, by means of which the base is mounted on thestationary framework.

According to a further embodiment which is preferred overall, at leasttwo interchangeable die receiving means are provided on a base of thetransfer station, wherein the transfer station additionally comprises astationary framework and wherein the base is movable with reference tothe framework by means of a standby drive in order to displace in eachcase one interchangeable die receiving means into a standby position.

In general, it is certainly possible to develop the control of a joiningtool such that the joining tool, where required, can approachsubstantially immovable interchangeable die receiving means at theirrespective positions.

In the case of the development of a standby drive, it is possible todisplace each interchangeable die receiving means, where required, intothe standby position such that the programming of a control means of thejoining tool is simplified as said joining tool can always approach thestandby position to take over interchangeable dies.

A development of this type is generally conceivable when the severalinterchangeable die receiving means are arranged in a linear manner.Said embodiment is particularly preferred, however, when theinterchangeable die receiving means are arranged on a circle such thatthe standby drive can be realized as a rotary drive.

A standby drive of this type can, as also the abovementioned die rotarydrive, be realized as a hydraulic drive, or also as an electromotivedrive.

According to a further preferred embodiment, which in conjunction withthe preamble of claim 1 represents its own independent invention, theinterchangeable die receiving means of the transfer station is realizedsuch that the interchangeable die is held at its die head and/or the dieshank protrudes in relation to the interchangeable die receiving means.

On the one hand, this enables the comparatively simple provision of arotary entrainment contour, namely preferably on the die head. Apositive locking connection can be realized between the interchangeabledie and the interchangeable die receiving means both in the axialdirection and in the circumferential direction by means of said contour.

On the other hand, said development enables the die shank to be freelyaccessible at the transfer station such that it is possible for thejoining tool to take it over by the joining tool being “slipped” ontothe die shank in the axial direction. As a result of the interchangeabledie being mounted in an axially positive locking manner in the transferstation, a defined axial position of the interchangeable die withreference to the joining tool can be set up as a result. A rotate/insertconnection between the interchangeable die and the joining tool can alsobe set up as a result of the rotating device in the case of said type oftakeover.

A further embodiment which is preferred overall provides that thetransfer station has associated therewith an ID sensor which is able todetect an ID feature which is provided on the interchangeable die.

In the case of said development it can be achieved that a system forcontrolling the joining tool system is preferably aware at all momentswhich interchangeable die is situated in the transfer station, inparticular in a certain interchangeable die receiving means of thetransfer station, and/or which interchangeable die is connected to thejoining tool. Process reliability can be increased as a result.

Provision for the joining tool system of an ID sensor which isassociated with the transfer station can be provided in general. Eachinterchangeable die receiving means preferably has associated therewithits own ID sensor.

In the case of the joining tool system according to the invention, it ispreferred when the joining tool is realized for the purpose of carryingout a joining process on a workpiece arrangement which is arranged on aninterchangeable die, wherein the joining tool is able to exert an axialforce onto the workpiece arrangement in a first axial direction andwherein the rotate/insert connection is realized at least in theopposite axial direction in a positive locking and/or non-positivelocking manner.

As a result of said measure it can be achieved that once a joiningoperation has been carried out, the interchangeable die does not “getcaught” inadvertently on the worked workpiece arrangement and in thisway is pulled inadvertently out of the die receiving portion of thejoining tool.

A rotary entrainment contour, with which a rotating device can cooperatefor rotating the interchangeable die and which is preferably realized onthe die head, is preferably realized on the interchangeable die.

By means of such a rotary entrainment contour it is possible, on the onehand, to rotate the interchangeable die in a targeted manner in order toset up the insert/rotate connection.

In addition, it is possible to hold the interchangeable die in atransfer station in a defined axial or rotational position as a resultof the rotary entrainment contour.

As a result of the rotary entrainment contour, the interchangeable die,in this case, can preferably be set in rotation (or be held in arotational position) in order to set up the insert/rotate connection.

According to a further preferred development, the interchangeable die isprovided with identification means which are optically detectable,and/or is provided with identification means which can generate acharacteristic acoustic signal which is acoustically detectable in thecase of a movement of the interchangeable die relative to a diereceiving portion.

In general, the identification means can also be formed by RFID means.Finally, it is also conceivable to detect the identity of aninterchangeable die just as a result of its die feature which isdetected, for example, by means of a camera or the like.

Means to detect the identification means, such as an ID sensor, can bearranged on the joining tool and/or in a transfer station. In addition,means to detect the identification means can also be associated justwith the joining tool and/or the transfer station such that a joiningtool is able to move past said detecting means before a die is stored inthe transfer station and/or a die is taken over by a joining tool.

In the case of the joining tool according to the invention, it isparticularly preferred when the fastening device of the die receivingportion comprises a blocking member which can cooperate with a blockingportion of a fastening contour of the interchangeable die in order tosecure the interchangeable die on the joining tool in a positive lockingand/or non positive locking manner in the axial direction.

The blocking member, in this case, can be an element which is rigid withreference to the die receiving portion.

It is particularly preferred when the blocking member projects into ashank receiving means of the die receiving portion.

A development of this type is preferred in particular when a fasteningcontour is formed on the interchangeable die by an axial recess and/or atransverse recess or a helical recess in the die shank.

In addition, it is altogether advantageous in the case of the joiningtool according to the invention when there are provided tool latchingmeans, which are realized for the purpose of interacting with dielatching means in order, in a latching manner, to secure aninterchangeable die which is received in the die receiving means in arotational and/or longitudinal position.

The tool latching means, in this case, can comprise in particular alatching element which is prestressed in the latching direction by meansof a spring, the latching element engaging in a suitable latching recessof the interchangeable die. In a preferred manner, the tool latchingmeans are arranged such that they can interact with die latching meanswhich are realized on a shank circumferential portion and/or on a shankend face of the interchangeable die which is remote from the die head,that is such that the tool latching means are arranged in the region ofa circumferential region or an axial end region of the shank receivingmeans. As a result, the tool latching means can be realized in a simplemanner as regards construction and production engineering. In addition,it is altogether advantageous in the case of the joining tool when thedie receiving portion is realized on a die holder which is releasablyconnectable in a rigid manner to a frame of the joining tool. In thisconnection, the die holder is preferably realized as a “dome” which, forexample, is connectable to a frame of the joining tool, for example to aleg of a C-frame, by means of a screw-type connection of the like. As aresult of the high forces occurring in the case of said joiningoperations, not only the interchangeable dies but also the die receivingportion are subject to a certain wear such that the releasableconnection to the frame enables simple exchange.

The present invention is in particular realizable without the geometryof the interchangeable die, the die holder or the frame of the joiningtool having to be enlarged. Automation of a die change can be achievedin a manner that is easy to realize. In a preferred development, theinterchangeable die is connected in a positive locking manner to thejoining tool in the axial direction in the connected state.

When two tangentially aligned pins are used as blocking elements in thedie receiving portion, an axial recess can be realized on the die shankby radially opposite parallel flattenings which proceed from the endface of the die shank.

A conical form in the region of the bottom shank region can facilitatesecure insertion of the die into the die receiving portion.

In general, the interchangeable dies can have an outer shape whichcorresponds substantially to standard dies.

It is obvious that the features that have been named above and thefeatures yet to be named below can not only be used in the combinationspecified in each case, but also in other combinations or standing alonewithout departing from the framework of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention are shown in the drawing and areexplained in more detail in the following description. The drawing is asfollows:

FIG. 1 shows a schematic side view of a first embodiment of aninterchangeable die according to the invention.

FIG. 2 shows a schematic cross sectional view along the line II-II ofFIG. 1, part of the head portion and an embodiment of a joining toolaccording to the invention additionally being shown.

FIG. 3 shows a representation corresponding to FIG. 1 of a furtherembodiment of an interchangeable die according to the invention.

FIG. 4 shows a representation corresponding to FIG. 1 of a furtherembodiment of an interchangeable die according to the invention and of afurther embodiment of a joining tool according to the invention.

FIG. 5 shows a sectioned view of the interchangeable die along the lineV-V of FIG. 4.

FIG. 6 shows a schematic representation of a joining tool system with atransfer station, in which several interchangeable dies according to theinvention are stored temporarily, and with a schematically indicatedjoining tool according to a further embodiment of the present invention,as well as with identification detecting means.

FIG. 7 shows a side view of an embodiment of an interchangeable dieaccording to the invention with a first form of identification means.

FIG. 8 shows a representation of the interchangeable die of FIG. 7 aftera rotation about 90°.

FIG. 9 shows a representation corresponding to FIG. 8 of a furtherembodiment of an interchangeable die with a further embodiment ofidentification means.

FIG. 10 shows a representation corresponding to FIG. 8 of a furtherembodiment of an interchangeable die with a further embodiment ofidentification means.

FIG. 11 shows a representation corresponding to FIG. 8 of a furtherembodiment of an interchangeable die with a further embodiment ofidentification means.

FIG. 12 shows a representation corresponding to FIG. 8 of a furtherembodiment of an interchangeable die with a further embodiment ofidentification means.

FIG. 13 shows a perspective view of an embodiment of a joining tool witha die holder according to a further embodiment of the invention as wellas a perspective view of an interchangeable die according to a furtherembodiment of the invention.

FIG. 14 shows a perspective view of another embodiment of transferstation in a transfer position.

FIG. 15 shows the transfer station of FIG. 14 in a locked position.

FIG. 16 shows a perspective schematic view of a further embodiment of aninventive transfer station.

FIG. 17 shows a schematic top view of a further embodiment of aninventive transfer station in a transfer position.

FIG. 18 shows the transfer station of FIG. 17 in a locked position.

FIG. 19 shows a schematic top view of another embodiment of an inventivetransfer station.

FIG. 20 shows a perspective, partially sectioned view of anotherembodiment of an inventive transfer station.

FIG. 21 shows a schematic top view on a interchangeable die receptacleof the transfer station of FIG. 20 in a transfer position.

FIG. 22 shows the interchangeable die receptacle of FIG. 21 in a lockedposition.

FIG. 23 shows a sectional view along the line XXIII-XXIII of FIG. 21.

FIG. 24 shows a schematic view of a joining tool including a work piecearrangement on which a joining process is to be conducted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 2 show a schematic representation from the side of anembodiment of an interchangeable die according to the invention which isgiven the general reference 10.

The interchangeable die 10 comprises a die head 12 which is preferablycircular in cross section, as well as a die shank 14 which is alsocircular in cross section. The diameter of the die shank 14 ispreferably smaller than that of the die head 12. A longitudinal axis 16is shown.

The die head 12 comprises a head end face 20 which is remote from thedie shank 14. A die feature 18 is realized on the head end face 20, forexample in the form of an axial recess, as is usual for punch rivetingor for other joining processes.

A rotary entrainment contour 22, which can be formed, for example, byone or two radial grooves which extend in a chord-like manner, isrealized on a circumferential portion 24 of the head of the die head 12.

A circumferential portion 26 of the shank is shown in FIG. 1. A shankend face 28 is remote from the die head 12.

A fastening contour 30 is realized on the die shank 14. The fasteningcontour 30 includes a first circumferential portion 32 which comprises ablocking portion 34. The blocking portion 34 can be realized on the dieshank 14, for example, by a transverse recess 35 which extends in thedirection transversely to the longitudinal axis 16. The fasteningcontour 30 additionally includes a second circumferential portion 36which is realized as release portion 38. The release portion 38preferably includes a longitudinal recess 39 which extends parallel tothe longitudinal axis 16. The first circumferential portion 32 and thesecond circumferential portion 36 connect to one another in thecircumferential direction such that a substantially L-shaped contour isproduced, as is shown in FIG. 1. The fastening contour 30 extends over acircumferential angle which is preferably smaller than 360° and inparticular is smaller than 180°. The circumferential angle preferablylies within a range of between 45° and 135°, in particular within arange of between 70° and 110°.

The interchangeable die 10 additionally comprises die latching means 42which are preferably realized on the die shank 14. The die latchingmeans 42 can be formed, for example, by a latching recess 44, as isshown in FIGS. 1 and 2.

Identification means 46 are preferably realized on the die head 12.

FIG. 2 shows a schematic sectional view in conjunction with a joiningtool 50. The joining tool 50 comprises a die receiving portion 52 whichincludes a shank receiving means 54 in the form of a recess. The insidediameter of the shank receiving means 54 corresponds to the outsidediameter of the die shank 14. In addition, the joining tool 50 includesa fastening device 56 which, in the present case, comprises a blockingmember 58 which extends in the radial direction into the shank receivingmeans 54. The blocking member 58 can be formed, for example, by a pin orthe like which is aligned radially.

The joining tool 50 additionally comprises a tool latching means 60which preferably include a latching element such as a ball 62 and aspring 64.

The tool latching means 60 can interact with the die latching means 42,as is shown in FIG. 2. In this connection, the latching element 62engages in a latching recess 44.

FIG. 2 shows the interchangeable die 10 in a rotational position B wherethe blocking member 58 engages in the blocking portion 34.

Prior to this, the interchangeable die 10 has been inserted in the axialdirection into the die receiving portion 52 by the die shank 14 havingbeen inserted into the shank receiving recess 54 such that the blockingmember 58 was aligned in the circumferential direction with the releaseportion 38. As a result, axial insertion was possible as the releaseportion 38 extends from the shank end face 28. The interchangeable die10 was then rotated with reference to the die receiving portion 52 suchthat the blocking member 58 passed into the blocking portion 34.Consequently an insert/rotate connection is set up. In this connection,the insert/rotate connection provides a connection which is positivelocking in the axial direction between the interchangeable die 10 andthe die receiving portion 52 in the position shown in FIG. 2.

In said position the tool latching means 60 are additionally inengagement with the die latching means 42 such that said relativerotating position is not inadvertently released (for example as a resultof the joining tool 50 making rapid movements).

A further embodiment of an interchangeable die is shown in FIG. 3 andgiven the general reference 10′. As regards design and method ofoperation, the interchangeable die 10′ corresponds in general to theinterchangeable die 10. Identical elements are consequentlycharacterized by identical references. It is essentially the differencesthat are explained below.

The interchangeable die 10′ comprises a die shank 14′ with a fasteningcontour 30′ which is realized in a helical manner on the outercircumference of the die shank 14′. The fastening contour 30′ extendsonce again from the shank end face and comprises a narrow secondcircumferential portion 36 with a release portion 38′, to which thehelical contour connects by way of the blocking portion 34′. In therotational position shown in FIG. 3, a blocking member 58 of a diereceiving portion 52 is situated in the region of an end of thefastening contour 30′. In said position the interchangeable die 10′ issecured axially by a combined positive and non-positive locking closurein relation to forces trying to withdraw it out of the die receivingportion 52. The blocking member 58 can be supported, in this case, onthe blocking portion 34′ which is realized by the helical groove on theouter circumference of the shank 14′. The pitch of the fastening contour30′ is preferably such that self-locking is not achieved. Accordingly,the rotational position relative to the die receiving portion 52 must beadditionally secured by a latching engagement, the latching forcepreferably being greater than in the case of the embodiment in FIG. 1.The manner of the latching means on the interchangeable die 10′ and thedie receiving portion 52, however, can otherwise be realized in asubstantially identical manner.

As also in the case of the preceding embodiment, a latching recess 44can also be realized in the region of the shank end face 28.

FIGS. 4 and 5 show a further embodiment of an interchangeable die 10″which corresponds generally to the interchangeable die 10 of FIGS. 1 and2 as regards design and method of operation. Identical elements areconsequently characterized by identical references. It is essentiallythe differences that are explained below. The same applies to a joiningtool 50″ which is shown in FIG. 4.

The interchangeable die 10″ comprises a die shank 14″ which is realizedwith a blind hole which proceeds from the shank end face. A blockingmember, which is given the reference 58″ in FIG. 4 and which forms thefastening contour 30″ of the interchangeable die 10″, protrudes in theinterior of the blind hole.

In the case of said embodiment, the joining tool 50″ die receivingportion 52″ includes a shank receiving recess 54″ which comprises afastening device 56″ in the form of a journal which projects axiallyfrom the bottom and is designed for the purpose of penetrating the blindhole 31 of the die shank 14″. A fastening contour 30″, 34″, and 38″ isshown in FIG. 5 and which, as regards the design, can correspond to thefastening contour 30 of the interchangeable die 10 in FIG. 1, isrealized on the journal 56″. In the case of said embodiment, thelocations of the blocking member 58 and fastening contour 30 between theinterchangeable die 10″ and the die receiving portion 52″ areconsequently reversed compared to the embodiment of FIG. 1.

The reference 58 in FIG. 4 indicates in a schematic manner a blockingmember, as would be used in the case of the embodiment in FIG. 1.

FIG. 6 shows a portion of a joining tool 50, the joining tool 50comprising a die holder 68 which is rigidly connected by means of areleasable connection 70 (for example a screw-type connection) to aframe 72 of the joining tool 50, for example a C-frame for punchriveting processes.

The die holder 68 is consequently exchangeable in a simple manner.

The die receiving portion 52, with the shank receiving means 54 and ablocking member 58 which projects into the shank receiving means 54, isrealized on the die holder 68.

A joining tool system 74 is formed by the joining tool 50 together witha plurality of interchangeable dies 10 and a transfer station 76.

The transfer station 76 serves for temporarily storing at least one, inparticular a plurality of interchangeable dies 10. FIG. 6 shows aschematic representation of a transfer station 76 in which twointerchangeable dies 10 can be stored. The transfer station 76 isconstructed such that the interchangeable dies 10 are arranged in alinear manner. It is obvious, however, that the interchangeable dies canalso be arranged along a circuit.

The transfer station 76 comprises a base 78 which comprises a firstinterchangeable die receiving means (receptacle) 80 and a secondinterchangeable die receiving means (receptacle) 82. The interchangeabledie receiving means 80, 82 are constructed identically in each case suchthat just the first interchangeable die receiving means 80 will bedescribed below.

The first interchangeable die receiving means 80 includes a U-shapedportion 84 which is rotatable relative to the base 78.

The U-shaped portion 84 is arranged substantially horizontally. TheU-shaped portion 84 is dimensioned such that a respectiveinterchangeable die 10 can be moved into the U-shaped portion 84 in thesubstantially horizontal position, in particular, however, in adirection transversely with respect to the longitudinal axis of theinterchangeable die 10. The U-shaped portion is additionally realizedsuch that it cooperates with the rotary entrainment contour 22 of theinterchangeable die 10 in order, in the received state, to hold theinterchangeable die 10 in the direction of rotation, in particular in apositive locking manner.

The interchangeable die 10 is held in the interchangeable die receivingmeans 80 such that the die shank 14 thereof is exposed, that is it isaccessible for a transfer into the die receiving portion 52.

The U-shaped portion 84 has associated therewith a rotating device 88.The U-shaped portion 84 can be rotated relative to the base 78 by meansof the rotating device 88 between the position shown in FIG. 6 where theU-shaped portion is open and a second position where the U-shapedportion 84 has rotated with reference to the base 78 such that theinterchangeable die 10 is surrounded in a circumferential manner in partby the U-shaped portion and in part by the base 78. As a result, theinterchangeable die 10 can be received in a locked manner in said secondposition in the transfer station 76.

The U-shaped portion 84 can also be rotated back again by means of therotating device 88 in order to open the interchangeable die receivingmeans 80 and to enable the interchangeable die 10 to be removed out ofthe transfer station 76.

The rotating device 88 can be an active rotating device 88. A rotarydrive which rotates the U-shaped portion 84 (and preferably all theU-shaped portion 84 at the same time) can be provided for this purpose.The rotary drive can be, for example, a pneumatic drive, an electricdrive or another drive.

The rotating device 88, however, can also be a passive rotating devicewhich simply makes rotation possible. In this connection, a drive forrotating the U-shaped portion can be effected, for example, as a resultof the tool 50 generating this type of rotational movement in a director indirect manner.

The base 78 is mounted on a stationary framework 90 by means of aplurality of elastic elements 92 such that the base 78 is mounted in afloating manner. This makes it possible for the base to carry outcompensating movements when placing interchangeable dies into storageand when removing them from storage. This increases the operatingreliability and reduces wear and tear.

The transfer of an interchangeable die 10 out of the transfer station 76into the die receiving portion 52 is effected as follows, the methodproceeding from a state where the interchangeable die 10 is locked inthe transfer station 76, the U-shaped portion 84 consequently beingrotated such that the interchangeable die receiving means 80 is closed.

In a first step, the tool 50 is moved (in particular by means of a robotor the like) such that the die receiving portion 52 is moved toward thedie shank 14, as is shown with the reference 94. The rotational positionof the tool 50, in this case, is chosen such that the blocking member 58is aligned with the release portion 38 of the fastening contour 30 inthe circumferential direction. Consequently, the die shank 14 is able tobe inserted into the shank receiving means 54. As soon as the blockingmember 58 is situated at the level of the blocking portion 34 (see FIG.1), when viewed in the axial direction, the U-shaped portion 84 isrotated by means of the rotating device 88, as is shown with thereference 96.

As a result of the rotational movement, the blocking member 58 istransferred into the blocking portion 34. At the same time, theinterchangeable die receiving means 80 is opened such that the U-shapedportion 84 is exposed, as is shown in FIG. 6.

The interchangeable die 10 can then be removed out of theinterchangeable die receiving means 80 in a direction transversely withrespect to its longitudinal axis, as is shown with the reference 98.

An interchangeable die 10 is placed in storage in the reverse sequence.First of all the interchangeable die is slipped in a translationalmanner into the open interchangeable die receiving means 80 by means ofthe tool 50 (against the direction of the arrow 98). The interchangeabledie 10 is then rotated by means of the rotating device 88 (against thedirection 96). As a result, the blocking member 58 is moved out of theblocking portion 34 into the release portion 38 of the fastening contour30. At the same time, the interchangeable die 10 is locked in theinterchangeable die receiving means 80. The tool 50 can then be removedaxially from the die shank 14, against the direction of the arrow 94.

In many cases it is desirable to know and to document whichinterchangeable die is situated where inside the joining tool system 74.To this end, as mentioned above with reference to FIG. 1, theinterchangeable die 10 can comprise an identification means 46.

In a corresponding manner, the joining tool system 74 can comprises anidentification means sensor 100 (identification detecting means) whichcan be associated with the transfer station 76 and/or the tool 50. TheID sensor 100 can be an optical sensor, such as a scanner, a camera orthe like. The identification means sensor 100, however, can also be anacoustic sensor (microphone) or an RFID sensor.

The identification means sensor 100 can be arranged next to the transferstation 76, as is shown in FIG. 6. In this case, the tool could be movedpast the identification means sensor 100 prior to an operation forputting into storage or to an operation for removing out of storage inorder to document the process for putting into storage or the processfor removing out of storage.

For increased security, however, it is desirable for eachinterchangeable die receiving means 80, 82, etc. to have associatedtherewith its own identification means sensor 100.

For the case where the identification means sensor 100 includes a cameraor an optical scanner, it is generally also conceivable not to provideany separate identification means 46 on the interchangeable die 10. Itis conceivable, rather, for the respective interchangeable die to beidentified as a result of its die feature 18.

FIGS. 7 to 12 show different types of identification means 46. FIGS. 7and 8 show an interchangeable die 10 with identification means 46 whichare realized in the form of radial grooves 102 on the outercircumference of the die shank 14. The grooves are characteristic ofeach interchangeable die. Means, which generate a noise when saidgrooves 102 are travelled over, are preferably provided on the joiningtool 50 in this case. Said means can be formed, for example, by the toollatching means 60 or other latching means. The characteristic noise canthen be received by an acoustic sensor which evaluates the acousticsignal to identify the interchangeable die 10.

FIG. 9 provides a view which is comparable to FIG. 8, grooves which areprovided with the reference 102 a in FIG. 9 also being used foridentification. However, the grooves 102 a in FIG. 9 are realized aslongitudinal grooves which provide a characteristic feature for theinterchangeable die 10.

FIGS. 10 to 12 in each case show optically detectable identificationmeans 46. FIG. 10, in this case, shows a barcode 102 b which is mountedon the circumferential portion 24 of the head. FIG. 11 shows a 2D code102 c which is mounted on the circumferential portion 24 of the head.FIG. 12 shows an alphanumeric code 102 d which is mounted on thecircumferential portion 24 of the head.

When mounting identification means 46 on the circumferential portion 24of the head, it is preferred when they are arranged between the rotaryentrainment contours 22 in the circumferential direction.

FIG. 13 shows a further embodiment of a joining tool 50 with a dieholder 68. An interchangeable die 10 is additionally shown here. Saidembodiments generally correspond to the embodiment in FIG. 1 as regardsdesign and method of operation. Identical elements are consequentlyprovided with identical references. It is essentially the differencesthat are explained below.

The interchangeable die 10 comprises a die shank 14 which includes acircumferential groove with an approximately triangular cross sectionfor forming the transverse recess 35. The release portion 38 is formedby two parallel, diametrically opposite flattenings which form thelongitudinal recesses 39 and of which only one is provided in FIG. 13.

A latching recess 44′, which is realized as a diametrical recess whichis triangular in cross section, is realized on the shank end face 28.

The die receiving portion 52 comprises two thin locking pin bores 106 atan axial height corresponding to the transverse recess 35. The lockingpin bores 106 are aligned tangentially to the shank receiving means 54.Two locking pins 108 are inserted into the locking pin bores 106. Thespacing between the locking pins 108 (shown by the reference D2 in FIG.13) corresponds, in this case, to the radial spacing between thelongitudinal recesses 39 of the interchangeable die 10. The spacingbetween the longitudinal axes of the locking pins 108 (shown by thereference D1 in FIG. 13) is preferably identical to the inside diameterof the shank receiving means 54.

The dimensions are consequently chosen such that the interchangeable die10 can be inserted into the shank receiving means 54 by way of its dieshank 14 in the representation shown in FIG. 13 as the longitudinalrecesses 39 fit precisely between the locking pins 108. As soon as thedie head 12 rests on the surface of the die receiving portion 52, thelocking pins 108 are situated at the axial height of the transverserecess 35 such that the interchangeable die 10 is able to be rotatedinside the shank receiving means 54, in particular about 90°, in orderto set up a positive locking insert/rotate connection in this manner.

To realize the tool latching means 60, a latching element is provided inthe form of a hollow bushing 62′ which tapers at its one end in awedge-shaped manner such that a latching cog is produced which is ableto engage in the latching recess 44′. As is shown in detail in FIGS. 14and 16, a spring element 64′, which is supported in the axial directionon a retaining pin 110, is arranged inside the latching element 62′. Theretaining pin 110, in this case, is inserted in the die holder 68 bymeans of a retaining pin bore 112 and in the latching element 62′ bymeans of longitudinal openings 116.

The mounting of said latching means 60 is comparatively simple as theshank receiving means 54 is preferably realized as an axially continuousbore in the die holder 68.

In addition, an ejection opening 114, which extends inclinedly upward inthe direction toward the shank receiving means 54 and which is realizedin the die holder 68, can be seen in FIG. 13. An interchangeable die 10can be forcibly ejected by means of the ejection opening 114 insofar assaid interchangeable die was clamped or the like in the die holder 68.

A fastening bore 118 for the releasable fastening of the die holder 68on a framework is shown in FIG. 13 with the reference 118, similar tothe function as shown in FIG. 6.

The following FIGS. 14 to 23 show further embodiments of transferstations which correspond in general to the transfer stations 76 of FIG.6 as regards design and method of operation. Identical elements areconsequently characterized by identical references. It is essentiallythe differences that are explained below.

The transfer station 76 shown in FIGS. 14 and 15 comprises a rotarydrive 121 for the rotating device 88. The rotary drive 121 is formed bya pneumatic cylinder 122, the piston rod 124 of which is connected to aslide 126. The slide 126 is designed for the purpose of moving U-shapedportions 84 of two interchangeable die receiving means 80, 82 between atransfer position 127, as shown in FIG. 14, and a locked position 128,as shown in FIG. 15.

In the case of the transfer position shown in FIG. 14, a joining tool 50can be inserted transversally into the interchangeable die receivingmeans (the interchangeable die receiving means 82 in FIG. 14) such thatthe U-shaped portion cooperates with the head of the interchangeable die10, more precisely with a rotary entrainment contour 22, in such amanner that the interchangeable die 10 is then held in a positivelocking manner in the interchangeable die receiving means 82 in theaxial direction and in the circumferential direction.

By rotating the U-shaped portions 84 of the transfer station 127 intothe locked position 128, as shown in FIG. 15 with the reference 96′, theinterchangeable die 10 can also be held in a positive locking manner inthe radial direction in the transfer station 76.

As a result of the rotational movement 96′, the interchangeable die 10is rotated inside a die receiving portion of the joining tool 50, from ablocked position into a release position such that the joining tool isthen able to be pulled from the die shank of the interchangeable die 10in the axial direction, as is shown in FIG. 15 with the reference 94′,in order to release the previously set-up rotate/insert connectionbetween the interchangeable die 10 and the joining tool 50. Aninterchangeable die 10 is transferred out of the transfer station 76 inprecisely the reverse sequence.

FIG. 16 shows a further embodiment of a transfer station 76 which cancorrespond in general to the embodiment of FIGS. 14 and 15 as regardsdesign and method of operation. In this connection, however, the base 78of the transfer station 76 is not secured directly on a stationaryframework 90 by means of elastic elements 92. Rather, the base 78 issecured directly, or by means of elastic elements 92, on a carriage 130which is able to be displaced with reference to the stationary framework90, as shown in FIG. 16 with the reference 132. As a result, it ispossible to displace each interchangeable die receiving means 80, 82into a standby position which is shown in FIG. 16 with the reference 134such that a joining tool just has to be adapted or taught to onetransfer position with reference to the transfer station.

A standby drive for displacing the carriage 130 with reference to thestationary framework 90 is indicated schematically in FIG. 16 with thereference 136. Said standby drive 136 can be realized in a pneumatic orelectromotive manner.

FIGS. 17 and 18 show a further embodiment of a transfer station 76. Saidtransfer station comprises a slide 138 which is displaceable axiallywith respect to the base 78 and on which a U-shaped portion 84 isdisplaceably mounted. The U-shaped portion 84 is coupled with the base78 by means of a gear unit 140. The gear unit 140 can comprise, forexample, a member which is pivotably mounted so as to be pivot on thebase 78 and pivotably mounted so as to pivot on the U-shaped portion 84.When a joining tool 50 moves an interchangeable die 10 in the transversedirection into the U-shaped portion 84, the slide 138 is displacedparallel thereto into the base 78, which results in the U-shaped portion84 being rotated by means of the gear unit 140, as is indicated in FIG.17 with an arrow.

This type of transfer station consequently provides a passive rotatingdevice 88 such that a separate die rotary drive, as the rotary drive 121in FIGS. 14 and 15, is not necessary.

In the case of the above embodiments, several interchangeable diereceiving means 80, 82 are arranged in a linear manner. However, it isalso possible to arrange a plurality of interchangeable die receivingmeans 80, 82 along a circle. Such a concept is shown schematically inFIG. 19. In this connection, the base 78 can be circular, a plurality ofinterchangeable die receiving means 80, 82, etc. being provided on theouter circumference of the base 78. The base 78, in this case, ispreferably rotated by means of a standby drive 136 in order to move adesired interchangeable die receiving means into a standby position,similarly as is shown in FIG. 16. In addition, a transfer station ofthis type can also have associated therewith a rotary drive 121 whichcan rotate U-shaped portions of the respective interchangeable diereceiving means between a transfer position and a locked position. Twoschematic pneumatic cylinders which can fulfil said function areindicated in FIG. 19 for this purpose. The standby drive 136, in thiscase, could operate in a stepped manner.

As an alternative to this, however, a standby drive 136 and a rotarydrive 121 can also be formed by an electric motor or by two electricmotors. When one electric motor or one other individual rotary drive isused, it is also possible to realize the two functions (rotating the dieand rotating into a standby position) by means of free-running or thelike.

FIGS. 20 to 23 show a further embodiment of a transfer station 76 whichis suitable in particular for interchangeable dies, as are shownschematically in FIG. 3. In this connection, a U-shaped portion 84 canpreferably be supported on a base 78 of the transfer station 76 by meansof an axial bearing 146. A rotary drive is not necessary in thisconnection. For in the case of a relative axial movement 94 between thejoining tool and the interchangeable die 10′, a relative rotation of theinterchangeable die 10′ is automatically brought about, as is shown inFIG. 20 with the reference 96.

The transfer station 76 additionally comprises for each interchangeabledie receiving means 80, 82, etc. in each case its own ID sensor which ispreferably realized such that it is able to detect an identificationmeans which is realized on the die head of an interchangeable die whichis received in the interchangeable die receiving means.

FIG. 24 finally shows a joining tool 50 with a C-frame 150, on the oneleg of which a joining tool, such as for example a punching tool 152, ismounted which is designed to exert an axial force 154. A die receivingportion 52 for receiving an interchangeable die 10 is realized on theother leg of the C-frame.

A joining operation is carried out by a workpiece arrangement 156 beingplaced onto the interchangeable die 10 and the axial force 154 thenbeing exerted onto the workpiece arrangement 156.

In this connection, material from the workpiece arrangement 156 canpenetrate into a die feature 18. When the workpiece arrangement 156 isreleased from the interchangeable die 10, in this case, axial forces canoccur. The interchangeable die 10 is prevented from being released fromthe die receiving portion 52 in this connection as a result of therotate/insert connection between the interchangeable die 10 and the diereceiving portion 52.

Although exemplary embodiments of the present invention have been shownand described, it will be appreciated by those skilled in the art thatchanges may be made to these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe appended claims and their equivalents.

What is claimed is:
 1. A transfer station for temporarily storing aninterchangeable die defining a longitudinal axis and including a diehead and a die shank, and wherein the interchangeable die can be takenout of the transfer station by a joining tool to carry out a joiningoperation which uses the interchangeable die and can be returned to thetransfer station again once the joining operation has been carried out,said transfer station comprising: a base; a die receptacle located onthe base and open in a radial direction transverse to the longitudinalaxis and into which the interchangeable die can be inserted in theradial direction transversely with respect to the longitudinal axis; arotating device operable for rotating the die relative to the base forpresentation to and engagement with the joining tool; and a U-shapedportion located in the base and partially around the receptacle; and theU-shaped portion is rotatable in relation to the base between a transferposition, wherein the U shaped portion is open in the radial directionand a locked position, wherein the U-shaped portion closes thereceptacle in the radial direction; and in the transfer position theinterchangeable die is insertable into the die receptacle, and in thelocked position the die is held securely in the transfer station.
 2. Atransfer station according to claim 1, and further comprising astationary frame, and the base is mounted to the frame in a floatingmanner.
 3. A transfer station according to claim 1, wherein the dieincludes a rotary entrainment contour partially defined in acircumferential portion of the die head by a chord-like groove, and: thedie receptacle is configured to hold the die by the entrainment contour.4. A transfer station according to claim 1 wherein the die receptacle isconfigured such that the die shank protrudes in relation to the diereceptacle.
 5. A transfer station according to claim 1, and furthercomprising an ID sensor operable to read an ID device located on theinterchangeable die.
 6. A joining tool system comprising: a plurality ofinterchangeable dies, each of a die defining a longitudinal axis andincluding a die head and a die shank; a joining tool including a diereceiving portion operable for engaging a die; and a transfer stationincluding: a base; a die receptacle located on the base and open in aradial direction transverse to the longitudinal axis and into which theinterchangeable die can be inserted in the radial direction transverselywith respect to the longitudinal axis; a rotating device operable forrotating the die relative to the base for presentation to and engagementwith the joining tool; a U-shaped portion located in the base andpartially around the receptacle; and the U-shaped portion is rotatablein relation to the base between a transfer position, wherein the Ushaped portion is open in the radial direction, and a locked position,wherein the U-shaped portion closes the receptacle in the radialdirection; and in the transfer position the interchangeable die isinsertable into the die receptacle and in the locked position the die isheld securely in the transfer station; and wherein the plurality of diesare connectable in each case to the die receiving portion of the joiningtool by an engagement motion including an insert movement and a rotatemovement; and the rotate movement is between an angle of relativerotation of 45° to 135° between the interchangeable die and the joiningtool.
 7. A joining tool system according to claim 6, wherein the joiningtool is operable for executing a joining process on a workpiecearrangement which is arranged on the interchangeable die, and whereinthe joining tool is operable to exert an axial force onto the workpiecearrangement in a first axial direction, and wherein the insert movementis realized in the opposite axial direction in one of a positive lockingor non-positive locking manner.